<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>程序员常用样式</title>
		<style type="text/css">
			.mydiv{
				width: 300px;
				height: 300px;
				background-color: #008000;
				color: aliceblue;
				/* 让div居中 */
				margin: 0 auto;
				 /* 让文字居中 */
				text-align: center;
			}
			
			.uname {
				width: 400px;
				height: 35px;
				border-radius: 5px;
				/* border: 1px solid red; */
				border: 2px dotted black;
				background-color: azure;
			}
		</style>
	</head>
	<body>
		<h1>背景样式</h1>
		<div class="mydiv">
		今天天气不错！
		</div>
		<input type="text" name="" id="" value="" style="background-color: red;" />
		
		<h1>边框样式</h1>
		用户名<input type="text" class="uname" name="" />
		
	</body>
</html>
